Letter stripping means



A. BURCKHARDT LETTER STRIPPING MEANS Jan. 25, 1944.

Filed April 11, 1342 VVVVVVVVVVVV ATTORNEY Patented Jan. 25, 1944 Pitney-Bowes Postage Meter Conn., a corporation of Delaware Stamford,

Application April 11, 1942, Serial No. 438,624

2 Claims. (01. 271-3 This invention relates to a device for stripping the lowermost letter from a stack of letters in a mail handling machine.

The usual procedure employed in stripping letters prior to the feeding of same through a mailing machine, is to provide some frictional means which is adapted to be moved intermittently into engagement with the lower surface of the lowermost letter to frictionally engage the letter and move same past suitable separator means to a feeding position. Such feeding devices have been commonly known as bump feed members and generally comprise a raised portion on the pulley structure which, upon each rotation of the pulley, will raise the frictional belt surface into wiping contact with the lowermost surface of the letter and effect stripping of the letter. This required that the belt be made of some stretchable material, such as rubber, in order that the belt might stretch while the bump portion of the pulley was in contact therewith, and might contract after the bump portion moved out of engagement with the belt. Such contraction and expansion of the belt was found to interfere with the feeding alignment of the letters in that there was a tendency' for the letters to shift.

In the device of the present invention, the method of feeding is the reverse of that effected by socalled bump feeding. Instead of providing means which will periodically move into engagement with the lowermost letter, it is now proposed to arrange the letter with relation to the stripping means in such manner that the lowermost letter will normally engage the said stripping means, and to further provide meanswhereby such engagement is prevented during a predetermined portion of each letter feeding cycle.

It is the principal object of the invention therefore, to provide in a letter stripping device, means whereby the letters are normally adapted to be engaged by the stripping medium, such as to normally provide for continuous stripping, and to periodically prevent stripping by means which is adapted to displace the lowermost letter from feeding relation with the stripping means during each operating cycle.

It is a further object to provide a letter stripping device wherein the letters are normally adapted to engage a stripping member and to further provide a shielding means in such manlustrated in the accompanying drawing-wherein:

feeding and stripping mechanism; p r Fig. 2 is an enlarged end view of a pulley with beltthereover, as taken inthe'direction; of the arrow 2' oniFig; l, and particularly showing the lettershi'elding means; i

Fig. 1 is a front elevational view showing letter V Fig. 3 is an enlarged View of a" portion. of Fig. 1

s ow n the st i pin t lower ette d theadvancementof same to adetterfeedihgposin; nd V i Fig. dis a view similar to Fig. 3, showing the non-stripping position with the' lowermost letter raised out of the path of the frictional surface ofithe st ippi m 'a J Referring now to the dra'wing in detail, there is shownin'Fig, l a'letter' feed belt lfl mo'unted up orra large pulley l] and a small pulley I 2, the latter pulley being adapted to be driven in any convenient manner. 7

Cooperating with the feed belt 10 is another feed belt; l3 suitably supported upon pulleys, one of which is shown at l4, and is adapted to" be driven in any convenient manner.

' A letter feed hopper is provided to support" a stack of letters [5 in such manner that the forward ends thereof will be directed angularly downward and positioned directly above the pulley ll. Said hopper includes a side guide wall 16, extending upwardly from a horizontal letter feed plate I1, and a front guide wall I8 having the lower end thereof spaced from the letter feed plate I! to provide an opening for the letters to pass through during a stripping operation.

Separator means is provided to restrict the passage of all but the lowermost letter when stripping is effected. Any suitable form of separator may be used, the structure herein shown 111C111d1 the surface of the lowermost letter. is prevented however, when the lowermost suring frictional surfaced wheels [9, positioned at either side of the belt III, as indicated in Fig. 2, and being normally arranged in a suitable form of yieldable mounting. A fence 2|, common to separator devices, is provided to prevent crowding of the leading edges of the lowermost letters against the frictional surfaces of the separator rollers.

As thus far described, the mechanism referred to is generally in common use and thus forms no direct part of the present invention.

It will be noted from the arrangement disclosed, that the leading edge of the lowermost letter normally rests upon the frictional surface of the feed belt It) at substantially the center of the pulley II. By this arrangement, the belt 10, in passing over the pulley II, is normally adapted to act as a stripping medium. In feeding letters to a postage printing device, however, it is necessary to time the stripping of letters. Where bump feed devices are employed, such timing is normally accomplished by the position of the bump feeding portion. s

In the present device, it is the object to utilize only a predetermined length of the feeding surface of the belt for stripping during each rotation of the pulley II, and to provide means to prevent contact between the belt and letters when stripping is completed, by shielding the frictional surface of the belt at the letter engagyond the belt surface. A portion of the peripheral edge of'each disc is also cut away, as at 23, to permit a predetermined portion of the belt surface to remain exposed. The length of the exposed portion is determined by the distance required to feed the letter during stripping, to the feed belt I3.

. Upon rotation of the pulley ll therefore, stripping and initial feeding of the letter will be effected at the location of the upper surface of the pulley ll so long as the belt is exposedto Strippin face of the letter is engaged by the peripheral surface portions of the discs which project beyond'th e belt surface. Said projecting disc portions, upon contacting the letter, will displace same from'the normal belt engaging position.

exposed. I

By means of the above described arrangement of, letter stripping, improved letter feeding has resulted. 'Sudden agitation of the letter at the moment of stripping, such as experienced with bump feed devices with their tendency to throw letters out of alignment at the moment of stripping, is eliminated, and the stretch and contraction of the belt with its detrimental effects previously referred to, is overcome.

Having described the invention, what is claimed is:

1. In a letter stripping device, driven frictional feed means including a driven pulley having a frictionally surfaced belt moving horizontally therefrom, means to support a stack of letters above the pulley with the lowermost letter engaging the belt thereon to normally effect letter stripping, and a flanged portion on said pulley extending above the frictional surface of the belt for a distance less than th entire circumference thereof, whereby the lowermost letter is raised above the frictional surface of the belt when said flanged portion is in engagement therewith, and whereby the letters return to their normal lowered position after the flanged portion passes beyond'the lowermost letter to thereby effect intermittent letter stripping.

2. In a letter stripping device, means to stack letters in a superimposed order with the leading ends thereof directed angularly downward, a letter stripping member comprising a rotatable member having a frictional letter engaging surface thereon with the frictional surface thereof normally disposed in the plane of the leading end of the lowermost letter to effect stripping of said letter, and shielding means movable with the rotatable member and having a substantially frictionless letter engaging surface projecting beyond the frictional letter engaging surface for a distance less than the circumference of the rotatable member, whereby the lowermost letter is maintained in a position removed from the frictional letter engaging surface during a portion of the rotation of the rotatable member, then is permitted to bear upon the frictional surface during another portion of the rotation thereof to effect stripping.

3. In a letter stripping device, means to stack letters in a superimposed order with the leading ends thereof directed angularly downward, a letter stripping member comprising a pulley having a frictional letter engaging surfac thereon with the upper surface thereof normally disposed in the plane of the leading end of the lowermost letter to effect letter stripping, and shielding means including discs movable With'the pulley at either side thereof and having a substantially frictionless letter engaging surface'projecting beyond the frictional letter engaging surface for a distance less than the circumference of the pulley, whereby the lowermost letter is maintained in a position removed from the frictional letter engaging surface during a portion of th rotation of said pulley, then is permitted to bear upon the frictional surface during another portion of the pulley rotation to effect stripping.

ALFRED BURCKHARDT. 

